gation is unnecessary, since there will be no gross soiling of 

 the sick room with discharges, and occasional germs coughed 

 out onto the floor or wall will soon die out and disappear. 



Each communicable disease has its own definite period of 

 TT T <;* Xc duration, and experience teaches that a cer- 

 P 1 <*h 1H * a * n num ^ er °f days or wee ks must pass be- 

 "R T 1 t H ^ ore ^ * s sa ^ e ^ or *^ e P a ^^ en ^ ^° m ingle with 

 other people. The periods of isolation for 

 the more common communicable diseases are shown in the 

 following table. In each case, of course, the patient should 

 be isolated until he has entirely recovered from the disease, 

 and running of the nose and ears has ceased. In diphtheria 

 the only safe rule is to wait until tests made by a bacteriolo- 

 gist show that the nose and throat are free from diphtheria 

 germs. 



Isolation Periods of Common Communicable Diseases 



_ . Isolation Period from Time 



of Beginning of Attack 



Chickenpox 12 days 



German measles 8 days 



Measles 10 days 



Mumps 2 weeks 



Scarlet fever 30 days 



Whooping cough 8 weeks, or until one week 



after last whoop 



The fact that many diseases are particularly catching just 

 _ 4 when they are beginning makes it very im- 



8 portant to watch for the onset of disease 



: ** and to start isolation as soon as possible. 



Measles, for instance, begins like an ordi- 

 nary cold in the head, with sneezing and running nose and 

 eyes. It has been shown by the investigations of Anderson 

 that there is far more danger of spreading the germs of 

 measles at this time than there is later, when a rash has 

 appeared and the patient has been put to bed. 



36 



